It's not entirely ridiculous, because weather greatly affects home runs.

There's another aspect of it though because it's not just about temperature but also barometric pressure. And if you're playing underneath the center of a 1028 mb high pressure cell, with all the sinking air, that will suppress home runs even if that air is warm and dry. On the other hand if you're on the edge of that cell, and it's pushing warm, humid air from your southwest, you're probably going to see an increase in home runs.

But there's way too many variables to confidently attribute anything to climate change.